The present invention relates to a dynamic pressure bearing using porous material.
This type of dynamic pressure bearing has conventionally been provided in which a sleeve for supporting a shaft is made by a sintering process of metal powder and in which dynamic pressure grooves are formed by a metal mold pattern for the sintering process.
However, in this conventional dynamic pressure bearing having a sleeve of sintered metal, many pores are present in the sintered metal. Therefore, fluid pressure escapes outside through pores of the dynamic pressure grooves, causing a problem that sufficient dynamic pressure can not be generated.